Cost-effective Energy Conservation System

ABSTRACT

A cost-effective, passive system for conserving energy during hot, summer months is presented. Earlier inventions in this area such as the attic fan (U.S. Pat. No.  2,746,674 ) worked by forcing the hot attic air out whenever the attic air temperature reached a predetermined level. The present invention works differently; by preventing heat buildup within the attic. A simple, mechanical system is designed to cover a large portion of the roof with a cloth like synthetic material that has a smooth, light-colored, reflective surface reflecting most of the incident solar energy during the months when the weather is hot. An air gap between this reflective surface and the roof further insulates the roof from the solar heat. This prevents build up of the super heated air in the attic thereby lowering the energy bills to cool the house and conserving energy. During the cooler months, this reflective surface covering the roof is fully or partially retracted as needed.

BACKGROUND OF INVENTION

Energy costs to cool structures (e.g. houses, offices, condominiums) inorder to maintain an optimal temperature inside when it is hot outsidecan be significant. The seasonal, peak demand imposed upon theelectrical grid by the air conditioners during the hot summer daytimemonths necessitate bigger power generating stations than would otherwisebe necessary. This results in pollution and degradation of environmentwhen conventional fuels such as coal, natural gas, oil or nuclear areused.

The field of the present invention relates to reducing cooling energybills for structures such as houses, condominiums, and offices etc.thereby conserving energy.

Earlier inventions such as the attic fans and the whole house fansworked by automatically operating when the heated attic air reached acertain set temperature. The operation of such fans threw out the superheated attic air that was then replaced by the comparatively cooleroutside air. At this point, the fan stopped running. With the attic nolonger as hot, it took the air conditioner less time and thereforecorrespondingly less energy to cool the house. The sum total of theenergy required to run the attic or whole-house fan and the airconditioner was thus less than would otherwise be the case to reach agiven lower temperature within the house. These inventions suffer fromthe following drawbacks a) the roof shingles and the correspondingunderlying structure still goes through large temperature swings therebyreducing its life. b) the action (i.e. the fans becoming operational) istaken in response to the cause (i.e. super heated attic air) while noattempt is made to mitigate the cause. c) some energy is used for theoperation of the fan.

Roof top vegetation aims to conserve energy by now allowing the roof toget hot with the incident solar energy and also reduces the pollution.Its principal drawback is the requirement that the roof be flat. It istherefore more suited for high-rises in the cities.

SUMMARY OF INVENTION

Roof shingles are typically dark and rough and easily absorb solar heat.Especially in areas that experience summer temperatures in excess of 80degree Fahrenheit significant energy savings can be obtained bypreventing the roof from absorbing the incident solar energy during thehot summer months. It is therefore the principle objective of thepresent invention to provide an mechanism to prevent heat buildup in theattic.

A cloth like synthetic material is stretched over the roof during thesummer months to shield it from the sun. The smooth, light-colored,reflective surface of this material shall reflect most of the solarenergy back and prevent it from reaching the roof. The air gap betweenthe reflective material and the roof will further insulate the roof fromthe solar heat. Since the covered roof will now remain much cooler thanit would otherwise, it will prevent the attic air from heating up to thesame extent, as it would have without the benefit of this invention. Thetemperature buildup within the attic will also have a lower gradient.Both of these factors combine to allow the household air conditioner torun for shorter durations in order to achieve a given lower temperature.This results in lower cooling energy bills and conservation of energy.

Another incidental benefit of the present invention is that it shieldsthe roof from rain if the synthetic material is waterproof. This maymitigate water damage to the house if the roof has leaks in it.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an isometric view of the system during the summer months whenthe roof is totally covered by the reflective surface.

FIG. 2 is a plan view of the system during the summer months.

FIG. 3 is an isometric view of the system during the winter months whenthe reflective surface is totally retracted.

FIG. 4 is a plan view of the system during the winter months.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate the end result after the present system hassuccessfully operated and completely covered the roof. FIGS. 3 and 4illustrate when the roof is completely uncovered. The numbering systemused to identify entities is consistent across all the figures.

As shown in FIGS. 1 and 2, rollers 1 a and 1 b shaped like dumbbells andrunning along the complete length of a section of the roof 6, are firstmechanically mounted at two endpoints on the corresponding roof section.Such roller pairs can be mounted on as many roof sections as is deemednecessary by the user. The reflective cloth-like material 2 (in FIG. 1and 2) is wound around roller 1 b. This cloth-like covering material haseyelets 8 at one end along its edge to which strings 9 are attached asshown in FIG. 2. The strings get wound around roller 1 a. Both therollers 1 a and 1 b are operated by small motors 5 b and 5 arespectively. These motors can either be manually operated or connectedto a thermostat and controlled automatically. The motors 5 a and 5 b mayuse a standard belt mechanism 4 a and 4 b as shown in FIG. 1 to drivethe rollers 1 a and 1 b. The belt mechanism is for illustrative purposesonly and any other suitable transmission mechanism may be utilized toturn the rollers. A limit-switch mechanism may be utilized to stop themotors automatically when the roof cover is either completely retractedor vice versa and is not shown in the figures. Friction pads against therollers 1 a and 1 b (not shown in the figures) may also be mounted sothat when the rollers turn the roof cover is held taut.

At the start of the summer, motor 5 b is activated. The belt drive 4 bturns the roller 1 a to pull the reflective roof cover from roller 1 b.The motor may either be manually stopped at any point to control theamount of roof (area) covered or it automatically stops when the entireroof section is covered due to the operation of a limit switch. Sincethe roof covering is smooth, light-colored and shiny it reflects most ofthe incident solar energy and prevents the roof from absorbing the solarenergy. The air gap 3 (shown in FIG. 1) also acts as an insulator. Thiskeeps the attic 7 (shown in FIG. 1) cooler than would otherwise be thecase.

During the colder months, motor 5 a is activated. The belt drive 4 aturns the roller 1 b to wind the reflective roof cover. The motor mayeither be manually stopped at any point to control the amount of roof(area) covered or it automatically stops when the entire roof section isexposed due to the operation of a limit switch. Since the roof is nowexposed, it can absorb all the incident solar energy.

1. A passive apparatus to prevent the heating of roofs and the attic airunderneath it during the hot season by reflecting the incident solarenergy:
 2. The apparatus provides an insulating air gap between thereflecting surface and the roof.
 3. The apparatus also shields the rooffrom rainwater if the material covering the roof is waterproof.
 4. Thesurface area of the roof covered shall be continuously adjustableallowing a fine control over solar heat energy absorbed by the roof. 5.The apparatus can be mounted on existing dwellings and structures. 6.The passive nature of the apparatus makes it very cost effective.